This invention relates to a golf ball which has a large carry.
Conventionally, various examinations have been made to optimize an arrangement, number and size (diameter and/or depth), of dimples on a golf ball to increase the carry of a golf ball. The present inventors, however, have discovered that while such factors as the arrangement, number and size of dimples are significant factors which influence the carry of a golf ball, the sectional shape and spatial volume of a dimple are also significant.
In particular, as illustrated in FIG. 1, a golf ball 20 has a large number of recessed dimples 1 formed on the surface thereof. The shape of a dimple of such a prior art golf ball is, in most cases, a parabolic curve (FIG. 2), an ellipse (FIG. 3) or a sine curve (FIG. 4) or a flattened trapezoid. The present inventors have learned that since any of these sectional shapes sharply intrudes into the surface of the ball, the air resistance becomes aerodynamically greater in comparison with the dynamic lift and hence the ball cannot make best use of momentum initially imparted thereto, resulting in an insufficient carry of the ball. Thus, the sectional shapes of the prior art golf balls do not make sufficient use of the initial momentum.